The so called "champagne method" for producing sparkling wine consists of adding to normal, unfoamy wine, which has undergone a first alcoholic fermentation, a decanting liquor containing sugar and fermentation yeast which causes transformation of the sugar into carbonic gas (CO.sub.2). Bottling may be effected either before or after the addition of the decanting liquor and yeast. Bottles are thereafter sealed by means of a hollow plastic plug inserted into the bottle neck and crimped on by means of a metallic cap.
The bottles are stored generally horizontally on "slats" for a long period ranging from several weeks to several months in cellars where the temperature is maintained constant generally between 12.degree. and 18.degree. C. This allows fermentation to develop with corresponding pressurizing or bubble production (i.e., foaming up) in the bottles.
During this long fermentation period each bottle must be shaken individually at repeated intervals to prevent fermentation deposits from adhering to the bottle walls. At the end of this period the bottles are stored on their head, i.e., the bottle neck is inclined downwardly to facilitate decantation of yeasts and to allow deposition of fermentation dregs within the hollow plastic plug in the bottle neck.
When fermentation is completed, the bottles are transported vertically with their necks down to a brine bath refrigerated and maintained at about -10.degree. C. The bottles are dipped into the icy bath to form by congealation a wine block of ice containing residues of the fermentation yeasts.
The bottles are submitted thereafter to a disgorging operation which consists of turning the necks of the congealed bottles up to a vertical position and then removing the caps thereby causing, due to the effect of higher pressure built up from gas formation within the bottle, ejection of the plastic cap together with with the attached ice block which contains the fermentation sediments. The level in the bottles is then restored by adding a dispatch liquor, and the bottle is sealed by a permanent plug which generally is a conventional cork oak plug.
The traditional champagne method which has just been described requires a large number of people particularly during fermentation for shaking the bottles, as this is often done manually. This method also involves a large ground surface for storage of the bottles and, due to the long storage times involved, this storage area becomes "tied up" sometimes up to a full year. Moreover, this method includes a step of congealing the bottle neck which is indispensable for elimination of yeasts.
Attempts have been made to try to remedy such disadvantages. For example, many devices have been devised to provide mechanical shaking of the bottles while disposed on movable pallets which permit the bottles to take any possible inclination from the horizontal position to the vertical position. These devices include means to rotate the bottles in all directions and under different inclinations. However, even if these devices can reduce the costs of labor, they require nevertheless significant investments which up to now have limited their commercial use.
Recently it has also been proposed to add yeasts into the bottles in the form of small balls of polymeric material, such as alginates, with yeast encapsulated therein. This process, however, has only been developed insignificantly until now because it involves a number of inconveniences. First an external material (i.e., the polymeric material) is added to the wine upon fermentation. Furthermore this process presents technical problems which have not yet been entirely solved. For example, poor retainment of yeasts in the balls enables a portion thereof to escape and precipitate in the wine thereby producing sediment. Finally, this process does not eliminate the need for the congealation and disgorging steps with the resultant loss of wine contained in the disgorged ice block.